Author's Notation: At the time of the Pike River explosion the company was mining very close to the Hawera fault. The articles below show this was a dangerous time for the miners and as they neared the Hawera fault, they faced the risk of potentially explosive methane gas.
On the day of the explosion all mining machinery was out of commission due to what Peter Whittall described as 'maintenance'. The author notes however that much of the machinery was new and in any event, a business is unlikely to schedule all machinery for maintenance at the same time. Because the machinery had automatic engine cut-offs when detecting too much methane in the air, could this be a reason to decommission the machinery?
If methane in the air was too high preventing use of machinery, is it possible that the company was taking short cuts
to get through hard rock by using shot blasting? If so, is it possible
this was the cause of the blast?
Peter Whittall acknowledges that the company was shot blasting on the day of the blast - refer to 'Peter Whittall' tab for video interview by Guyon Espiner of Mr Whittall. The extract of the interview is below:
GUYON How recently, if at all,
had you been shotfiring or blasting in the mine?
PETER We shotfire and
blast every day, we have done for a couple of years. We have procedures
for that. And on this particular day I understand we did a very small
shot on a piece of roadway where sometimes if you can't get a machine in to
mine it, and it's only small, you want a small little stub roadway, then
shotfiring's the most quick and efficient way. We had fired a shot at 11
o'clock, 11am, I believe. I haven't looked at the records, but I've asked
management on site, and was assured that the explosives and detonators had all
been booked out. Those that were used were accounted for, and those that
weren't used were returned and accounted for, and they were happy with the
procedures that were followed. So I have said before that, to my
knowledge and the knowledge of the management that have advised me, there's no
direct link between our shotfiring activities, and there was no shotfiring to
our knowledge going on at the time of the incident.
Author's Note: In the above interview Whittall states he had not looked at the shot blasting records. He states his managers had assured him they were all in order. It is highly unlikely and not credible that Whittall would not have checked the records of shot blasting. Given he was the CEO of the company and that the cause of the blast was under investigation, it can be expected with high probability he personally would have viewed all pertinent records. Were these records closely examined by police? Did police examine all risk management policies and verify procledures? Did the Department of Labour closely examine risk management policies and verify procedures?
In 1896 there was an explosion at the Brunner mine, an area close to Pike River (refer map above). Sixty-five men lost their lives. The resulting Royal Commission showed that the explosion was caused by a blown-out shot fired by someone on the morning of the disaster. Is Pike River mine an example of a further loss of 29 lives due to mining management failing to learn from past lessons? (Related extract of historic explosion below).
The possibility of the Pike River Mine explosion being caused by shot blasting was also referred to by Dave Feickert, a mine safety expert. Mr Feickert referred to this within the first fortnight of the explosion occurring. Refer to his article below.
Given the probability of the explosion being caused by shot blasting, how thoroughly did the Royal Commission of Enquiry focus on shot blasting practices by Pike River, historically and on the day of the explosion?
Reference to the Commission of Enquiry reports (Vol 1 and 2) shows a history of New Zealand mining fatalities with shot-blasting links, yet no findings were made by the Commission on shot-blasting by Pike River. Refer tabs 'Commission Reports'.
At the Strongman mine, blasting (or shot-firing) disturbed old workings and allowed a gas into the workings, so with knowledge of this problem in the Brunner seam, why did the company continue with shot-blasting at Pike River?Dave Feickert, mine safety expert A Wanganui-based mine safety expert reckons a Royal Commission of Inquiry into the Pike River tragedy could be asking questions that ensure safe work practices for all New Zealand miners in future.
Dave Feickert told the Wanganui Chronicle that one overarching question the commission should ask is whether the system of safety supervision in legislation and practice is sufficient to guarantee safety.
An explosion at the Pike River mine killed 29 miners and subsequent explosions have stymied any efforts to recover their bodies.
Mr Feickert has been recognised for his work helping to improve coal mine safety and health in China's accident-prone mining industry and working with other foreign advisers he has helped cut the accident rate by 70 per cent in the past five years.
He said the commission would probably ask what risk assessments Pike River Coal did before it began mining and what risk management systems it put in place to continually monitor those risks on a daily basis.
Mr Feickert said he also expected the inquiry to find out if Pike River Coal had a gas management plan in place from the moment it started mining near Greymouth, if it instituted a system to clear gas from the mine, and if not, why not?
"At the Strongman mine, blasting (or shot-firing) disturbed old workings and allowed a gas into the workings, so with knowledge of this problem in the Brunner seam, why did the company continue with shot-blasting at Pike River?" Mr Feickert said.
"There was an electricity outage reported immediately before the explosion. So is the company aware of the cause of this, or whether the miners restarted the system just before the explosion? "And the commission should be asking if there was any monitoring back to the control room or electricity supply in the pit."
He said it would probably want to know if any geological surveys were carried out on the likelihood of gas outbursts in the coal seam that Pike River was mining.
"The commission will also question the methods of gas monitoring that were in place at the mine too. The company's chief executive, Peter Whittal, has said there was continuous monitoring for methane in 'parts of the mine' so it's important to establish where."
Mr Feickert said the inquiry would probably want to be reassured about inspections of the mine, when these were carried out and who did them.
"Were there pre-shift inspections by mine deputies and where are their records over the last 12 months?
He expected the inquiry to be completed in about six months.
"The 5.5m -wide, 4.5m high tunnel had to pass through the Hawera fault - a
60m-wide zone of fractured rock with a risk of methane gas infiltration
sufficient to require flameproof mining equipment to be used."
Miners have hit more water than expected and potentially explosive
methane gas has also been found as the tunnel nears the Hawera fault,
where more fractured rock is expected, before miners hit the final run
to the coal seam.
Whittall is unperturbed by gas levels .... .
Methane gas has long been identified as a potential problem for
the Pike River Coal mine, as rescuers scramble to find up to 27 missing
miners following the explosion at the West Coast this afternoon.
Mines are notoriously susceptible to explosions.
The cause of today's blast has not yet been identified, but Pike River
Coal chief executive Peter Whittall - who oversaw much of the
development of the company's mine 46km northeast of Greymouth - started
the week promoting the mine's prospects to shareholders who went to the
company's annual meeting at the mine site.
Over the past year workers had to push their underground roadways
through a zone of rock and out into the coal seam: The company spent $4m
hiring extra engineers and miners, and bringing in a big reconditioned
Sandvik ABM20 single-pass continuous mining machine.
The company had recently completed commissioning the first of its two
main underground fans that had increased ventilation by around 30 per
cent.
Mr Whittall said the mine's "quite complex geological environment" would always "throw up challenges".
Unusually, the 2.3km mine shaft slopes uphill near the top of the
Paparoa Range and features two seams: the Brunner coal measures with
just over 58.5 million tonnes of recoverable coal, and the deeper
Paparoa measures with an additional eight million tonnes.
The 5.5m -wide, 4.5m high tunnel had to pass through the Hawera fault - a
60m-wide zone of fractured rock with a risk of methane gas infiltration
sufficient to require flameproof mining equipment to be used.
"Once the tunnel passes through the Hawera fault, expectations of
methane (albeit minimal and within approved safe operating limits)
associated with the fault zone and the coal measures to the west will
require that flameproof, specialist equipment be used," former chief
executive Gordon Ward said in June 2008.
Pike River has estimated that "fugitive" methane gas emissions from the
mine are likely to be approximately 1.4 million tonnes over the mine
life.
The tunnellers struck other trouble with a 108m deep, 4m wide
ventilation shaft in February 2009 when fractured rock dropped out of
the bottom third of the shaft, and the company had to spend $7m to
reinforce the shaft. It had to raise $45m to pay for this and the
absence of targeted coal production while the reconstruction was carried
out over eight months.
In full coal production, the mine planned for high pressure water
cannons to be used with the mining machines to sluice 2000 tonnes of
crushed coal each day to the pit bottom so that it could be started on
its export journey as a piped slurry.
- NZPA
